Many systems have been proposed heretofore for using some portion of the heat generated during the refrigeration cycle to heat ambient air or hot water for washing dishes or the like. However, these units are often very inefficient and only recover some portion of the waste heat. In addition, there is a danger when potable water is heated from the freon or other poisonous refrigeration gas, that the potable water will be contaminated. To avoid this problem, some systems have provided an intermediate fluid, and a separate spaced heat exchanger to isolate the freon from the potable water. Unfortunately this has the effect of significantly increasing the complexity of the system, as well as introducing further heat losses and lowering the efficiency of the system. One system for recovering heat from a large number of refrigeration units is shown in U.S. Pat. No. 4,041,724, in which the complexity of the required manifolding arrangements and the like should be noted. While some specialized units using special castings and heat exchange structures have been proposed for heating water from more than one refrigeration unit, these units have been relatively costly, and still must face the problems of possible potable water contamination.
Accordingly, a principal object of the present invention is to provide a simplified, improved and more efficient system for utilizing the waste heat from a number of refrigeration units to heat potable hot water, while still protecting the water against contamination by refrigeration gases.